[PATCH v2] generic/608: verify S_DAX is active immediately for DONTCACHE

[XiaoLi Feng <xifeng@redhat.com>]

From: Xiaoli Feng <xifeng@redhat.com>

After upstream linux patches(77573fa310d, 88149082bb8), if
FS_XFLAG_DAX is set, DONTCACHE is also set. So S_DAX on the file
should be active immediately once FS_XFLAG_DAX is set.
---
 tests/generic/608 | 38 +++++++++++---------------------------
 1 file changed, 11 insertions(+), 27 deletions(-)

diff --git a/tests/generic/608 b/tests/generic/608
index dd89d91c..92f368e0 100755
--- a/tests/generic/608
+++ b/tests/generic/608
@@ -6,7 +6,7 @@
 # Change FS_XFLAG_DAX on an existing file and check if S_DAX on
 # the file can take effect immediately by the following steps:
 # 1) Stop all applications which are using the file.
-# 2) Do drop_caches or umount & mount cycle.
+# 2) DONTCACHE is set.
 
 seq=`basename $0`
 seqres=$RESULT_DIR/$seq
@@ -36,7 +36,7 @@ _require_dax_iflag
 _require_xfs_io_command "lsattr" "-v"
 _require_xfs_io_command "statx" "-r"
 
-test_drop_caches()
+test_caches()
 {
 	local t_file=$SCRATCH_MNT/testfile
 
@@ -51,56 +51,40 @@ test_drop_caches()
 	_check_xflag $t_file 1
 	_check_s_dax $t_file 0
 
-	# One application is using test file and check if S_DAX on
-	# the file doesn't take effect immediately by drop_caches
-	echo 2 > /proc/sys/vm/drop_caches
-	_check_s_dax $t_file 0
-
 	exec 3<&-
 
 	# No application is using test file and check if S_DAX on
 	# the file takes effect immediately by drop_caches
-	echo 2 > /proc/sys/vm/drop_caches
 	_check_s_dax $t_file 1
 }
 
-test_cycle_mount()
+test_nocache()
 {
-	local option=$1
-	local t_dir=$SCRATCH_MNT/testdir
-	local t_file=$t_dir/testfile
+	local t_file=$SCRATCH_MNT/testnocache
 
-	mkdir -p $t_dir
-	$XFS_IO_PROG -c 'chattr +x' $t_dir
 	rm -f $t_file
 	touch $t_file
+	_check_xflag $t_file 0
+	_check_s_dax $t_file 0
+
+	$XFS_IO_PROG -c 'chattr +x' $t_file
 	_check_xflag $t_file 1
 	_check_s_dax $t_file 1
 
-	exec 3< $t_file
-
 	$XFS_IO_PROG -c 'chattr -x' $t_file
 	_check_xflag $t_file 0
-	_check_s_dax $t_file 1
-
-	exec 3<&-
-
-	# No application is using test file and check if S_DAX on
-	# the file takes effect immediately by umount & mount
-	_scratch_cycle_mount "$option"
 	_check_s_dax $t_file 0
 }
 
 do_tests()
 {
 	local mount_option=$1
-	local cycle_mount_option=$2
 
 	_scratch_mount "$mount_option"
 
-	test_drop_caches
+	test_caches
 
-	test_cycle_mount "$cycle_mount_option"
+	test_nocache
 
 	_scratch_unmount
 }
@@ -108,7 +92,7 @@ do_tests()
 _scratch_mkfs >> $seqres.full 2>&1
 
 # Mount with dax option
-do_tests "-o dax=inode" "dax=inode"
+do_tests "-o dax=inode"
 
 # Mount without dax option
 export MOUNT_OPTIONS=""
-- 
2.18.1